By 2355, Louvois held the rank of Commander. That year, she was the prosecutor in the court martial of Captain Picard held at Starbase 32 following the loss of the USS Stargazer after the Battle of Maxia. In her zeal to show that she could prosecute Picard without bias, she overcompensated by relentlessly attacking Picard and even brought up something Picard had said in bed. She was removed from the case, given a formal reprimand, and told to submit to a court of inquiry to determine any further charges. In response, Louvois resigned her commission. (TNGnovel: The Buried Age)

One of her first duties in her new command on Starbase 173 was ruling on the rights of androidLieutenant CommanderData. She based her ruling on previous decisions and ordered Data to submit to CommanderBruce Maddox, as he was the property of Starfleet. Captain Picard challenged the ruling. Being short staffed, Picard was appointed as Data's defense, with CommanderWilliam Riker forced to prosecute. She finally agreed that Data was not the property of Starfleet and had the right to choose. (TNGepisode: "The Measure of a Man")

Following Data's hearing, Louvois and Picard spent time together prior to the Enterprise departing Starbase 173 to survey planets in the area for possible colonization. (TNGnovel: Metamorphosis)

A few years later, Louvois would head toward a legal conference via shuttlecraft. Starfleet rules prevented JAG officers from piloting shuttlecrafts themselves, so Louvois selected Data to serve as her pilot despite the fact he would miss his first chance to visit a circus; Louvois believed Data to be "one of the best helmsmen in the fleet". The captain also chose to take the opportunity to apologize to Data regarding the situation about his potential disassembly. (TNGcomic: "The Rich and the Dead!")